Development and Optimization of Phoenix dactylifera Flavonoid-Loaded Mucoadhesive Nanoparticles for Mucosal Administration and Oral Cancer Cytotoxicity

Background and Objective: Mucosal cancers present significant therapeutic challenges due to limited drug permeation, rapid clearance and poor retention at epithelial sites. To overcome these limitations, this study developed and optimized Ajwa Extract Flavonoids Chitosan Mucoadhesive Nanoparticles (AEF-CMNP) from Phoenix dactylifera L. for localized mucosal delivery. Methods: Flavonoids were extracted from Ajwa dates and characterized using LC–MS, FTIR, and 1H/13C-NMR techniques. Nanoparticles were formulated via the ionic gelation method using chitosan and sodium tripolyphosphate (TPP), followed by systematic optimization using a Box–Behnken design (BBD) based Design of Experiments (DoE) approach. In vitro release profiles and 3-month stability studies were conducted. Cytotoxicity was evaluated via MTT assay across primary human oral keratinocytes (HOK), fibroblasts, and malignant cell lines including TR146 (buccal), CAL-27 (tongue), and HEp-2. Results: Characterization confirmed quercetin as the major flavonoid component. The optimized AEF-CMNP formulation exhibited a particle size of 226 nm, a PDI of 0.201 ± 0.01, a zeta potential of +24.8 mV and an encapsulation efficiency of 79.2%. Physicochemical analyses indicated non-covalent interactions and partial amorphization of the encapsulated compounds. In vitro drug release followed a controlled, biphasic pattern, characterized by an initial burst release of surface-associated flavonoids followed by sustained diffusion-controlled release from the chitosan matrix, achieving 93.50 ± 1.68 cumulative release within 48 h. Stability studies confirmed minimal variation in nanoparticle properties over three months, particularly under refrigerated conditions. Comparative cytotoxicity assays demonstrated significantly enhanced efficacy for AEF-CMNP compared to free flavonoids and control groups, yielding IC50 values of 54.9 µg/mL in TR146 cells and 43.7 µg/mL in CAL-27 cells. Conclusion: The developed AEF-CMNP system offers an effective and stable platform for delivering plant-derived bioactive, demonstrating strong potential for localized mucosal cancer therapy through improved cellular uptake and sustained retention. Further in vivo mechanism-based studies are warranted to validate clinical utility.